The invention relates to a multifunctional airburst explosive fragmentation munition with improved fragment spray aerial coverage and fragment mass distribution that can be launched from small, medium and large caliber high velocity gun systems. The technical feasibility of the present invention is based on recent advances in miniaturized electronic fuse control systems with improved intelligence and reliability, permitting a round to assess its position at a pre-determined location within approximately ±5 meters from target. This enables a munition to function in a number of modes including airburst mode, point impact mode, and delayed initiation mode. In the delayed detonation mode, the munition can act as a high-strength kinetic energy projectile capable of breaching light armor and reinforced concrete and masonry walls in urban terrain military operations.
In the airburst fragmentation mode, the munition is detonated in the air at a location near the target projecting fragments in a forward direction. This results in high fragment density in a radial distribution around the detonated shell, including the direction of travel, which maximizes the lethal area of the fragment engagement “footprint” at the target.
The present invention achieves an optimal use of materials for lethality requirements against a number of targets, including full body armor combat personnel, lightly armored combat vehicles, personnel carriers, mobile radar stations, urban structures, etc. Multifunctional capabilities are possible within a single round of ammunition, with destructive capabilities superior to current fragmentation approaches such as hand or rocket launched grenades and for both anti-vehicle and anti-personnel destruction. Such ammunition comprises projectiles with specially designed warheads in the frontal areas and can be 40 mM to 120 mM caliber Tank Rounds, e.g., or even in bullet form. The warheads ultimately break into pieces (fragments) which have comparatively higher velocity and relatively larger total mass than for instance, hand thrown grenades, greatly increasing the destructive power. Design of the warhead liner enables fragment direction of flight to be reasonably well chosen. A one-piece solid, high mass of material may be positioned in the front of the warhead which will fragment and it will spray the frontal and side targets with fragments. However, the fragments will all be relatively large in size and all about the same diameter. These larger fragments are good against a vehicle target. However, rather than a one-piece solid, high mass of material in front it is preferred to have such added material made up of one or more layers (“liners”) where each liner by itself is less in mass, but together all the layers constitute the desired high mass of material in front.
The liners create two types of fragments in one warhead, numerous smaller diameter fragments which are anti-personnel, plus higher mass larger diameter fragments, which are anti-vehicle, thus dual purpose, and can be similarly made for multiple purposes. The anti-personnel fragments, though smaller in diameter, are more numerous in the number of fragments than what would result from a one-piece, solid high mass of material in the front. The significantly larger quantity of fragments will spray the area well and although smaller in diameter, are adequate and thus preferred to do the anti-personnel function. The larger mass fragments, though fewer in number, are still adequate for the anti-vehicle function.
The projectile takes advantage of the extremely high launch velocities as contrasted to a hand thrown grenade. This propels at a greater velocity, plus with a larger mass than in a hand thrown grenade, mass in the front areas, which can be more successfully used for anti-vehicle, anti-personnel missions. The hand thrown grenade destructive ability is primarily due to its own explosion and disintegration, driving the pieces as fragments in various directions. A hand grenade's walls are relatively thinner to facilitate explosion, but that leaves comparatively less mass of the fragments from such thinner wall mass, to have the destructive power, and lower velocity in a (desired) forward direction compared to a round. As mentioned, in this invention relatively greater mass can be employed in a frontal warhead such as FIG. 4, FIG. 6A and FIG. 2C. More precise design of the warhead liner shapes that are employed in this invention, enable a finer result of directional choice for propelling the fragments.
It is possible to have near perfect coverage of moving fragments in the areas needed to successfully kill personnel and destroy vehicles (such as in FIG. 3D ideal front direction coverage), in a fan shape pattern looking down on a cross-section of the field of fragment distribution. The warhead liners' cross-sectional shapes, might be designed on a computer provisionally to follow a third order parametric polynomial curve (nine degrees of freedom). This mathematically modeled curve allows for more tailored shaping (through iterations) of the warhead shape which seems best in testing for superior kill results. It is further possible to design the warheads with embedded fragments of selected grain diameter sizes (FIG. 4) specially chosen for the targets, with chosen packing densities as a further factor in the warhead's lethality. For instance, smaller grain sizes adequate to kill personnel, and larger grain sizes are included as well, to kill light vehicles (or perhaps to destroy radar sights, missiles, armor, wooden or tile walls, or timber, clearing of a forest area, destroying gypsum, wood, masonry, concrete, brick or block walls in Urban Terrain Military Operations, being mission targets, e.g.). Various mechanisms are discussed which can cause successful breakup of the warhead into desired fragments of various sizes and velocities, including pre-embedding fragments (FIG. 4), scoring of the warhead outer surfaces (FIG. 5), or having small holes made in the warhead (FIGS. 6B-6G) such as by drilling small dimple-like holes in the projectile's front cap area, or employing multiple liner warheads (FIG. 6A). A brief description of the present invention is as follows.